JPH08112006A - Agricultural tractor work machine connection structure - Google Patents

Abstract

PURPOSE: To shorten the whole length of a agricultural tractor to reduce its revolution radial, when the tractor is connectd to a working machine. CONSTITUTION: In the agricultural tractor A provided with a crawler type travel device 1 and further with a working machine liftably connected thereto through a three link mechanism and a lifting mechanism, right and left lower pivotally supporting members for pivotally supporting the front end parts of the right and left crawlers of the crawler type travel device are disposed at positions which are forward from the rear ends of the right and left crawlers of the crawler type travel device and which are placed on the insides of the right and left crawlers, respectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a work implement connecting structure for an agricultural tractor.

[0002]

2. Description of the Related Art Conventionally, in an agricultural tractor which is equipped with a crawler type traveling device and is connected to a working machine in a rearward direction via a three-point link mechanism and an elevating mechanism, the three-point link mechanism is connected to that of the agricultural tractor. It is provided so as to largely project backward from the machine body.

Further, in the lifting mechanism, one hydraulic cylinder is linked to the left and right lower links of a three-point link mechanism, and the working machine is lifted and lowered by the expansion and contraction operation of the hydraulic cylinder.

Further, in the lifting operation of the working machine, the working machine is raised by extending the hydraulic cylinder by hydraulic pressure, and the working machine is lowered by draining the hydraulic pressure and by the weight of the working machine.

Further, the power take-off shaft for transmitting power to the working machine has only slightly protruded from the rear surface of the body of the agricultural tractor.

[0006]

As described above, since the three-point link mechanism is provided so as to largely project rearward from the body of the agricultural tractor, the total length when the working machine is connected to the agricultural tractor is long. As a result, the turning radius becomes large, which is inconvenient for handling.

Further, since the working machine is lifted and lowered by one hydraulic cylinder, it is difficult to lift and lower a wide working machine or a heavy working machine, and the left-right balance becomes unbalanced. There is.

Further, since the working machine is lowered by its own weight, there is a problem that the descending speed becomes slow and it takes time to lower the working machine.

Further, since the power take-off shaft only slightly protrudes from the rear surface of the body of the agricultural tractor, the drive shaft between the agricultural tractor and the working machine becomes long, and the weight increases. There is a problem that it becomes difficult to attach / detach the drive shaft, and further, adverse effects due to vibration accompanying the rotation of the drive shaft occur.

[0010]

According to the present invention, there is provided an agricultural tractor having a crawler type traveling device, and a working machine is movably connected to a rear side through a three-point link mechanism and an elevating mechanism at the rear, and the above three points are provided. The left and right lower pivot parts that pivotally support the front end parts of the left and right lower links of the link mechanism are arranged in front of the rear ends of the left and right crawlers of the crawler type traveling device 1 and inside the left and right crawlers. It is intended to provide a work machine connection structure for a tractor.

Further, the lifting mechanism is provided with left and right lifting hydraulic cylinders interlockingly connected to the middle parts of the left and right lift arms, and the rod side of the lifting and lowering hydraulic cylinder of the lifting mechanism is provided in the operating section. By connecting to the hydraulic pump via the oil passage switching valve connected to the switch, it is possible to change the operating direction of the left and right lifting hydraulic cylinders, and the power take-off shaft for transmitting power to the work machine is seen from the side. It is also characterized in that the crawler type traveling device is extended to the vicinity of the axis of the left and right driven sprockets arranged at the rear end portion thereof.

[0012]

Embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows an agricultural tractor A according to the present invention. The tractor A has a body frame 2 mounted on the upper surface of a crawler type traveling device 1 and a front portion of the upper surface of the body frame 2. The motor unit 3 is mounted, and a driver unit 6 including a steering handle 4 and a seat 5 is provided on the rear portion of the upper surface of the aircraft frame 2.
A cabin 7 enclosing the work machine B is mounted, and a work machine B is installed at the rear end of the machine body frame 2 via a three-point link mechanism 8 and a lifting mechanism 9.
The rotary cultivator as is is connected so that it can move up and down.

As shown in FIG. 1, the crawler type traveling apparatus 1 has a horizontal frame-shaped traveling frame 10 having left and right front sprockets 11 pivotally supported on the left and right front ends thereof. The left and right driven sprockets 12 are rotatably supported at the rear end, the upper roller 13 is rotatably supported on the upper surface of the traveling frame 10, and the two lower rollers 14 are respectively rotatably supported below the traveling frame 10. A pair of equalizers 15 is attached.

The left and right drive sprockets 11, the left and right driven sprockets 12, the left and right upper rolling wheels 13, and the lower rolling wheels 14
Left and right crawlers 16 are respectively wound around the outer circumference of ..., and a left and right drive sprocket 11 is interlocked with a left and right hydraulic motor 17 that forms part of a hydrostatic transmission HST, which will be described later. The power from the mounted engine 18 is changed by the above-mentioned hydrostatic transmission HST to change the left and right crawlers 16
The tractor A is made to travel.

FIG. 2 shows a hydraulic circuit. The hydrostatic transmission HST is composed of variable displacement left and right hydraulic pumps 20, 20 which are interlockingly connected with an engine 18, and left and right hydraulic motors respectively.
17,17 are connected to each other so that the left and right hydraulic pumps 20,20 can be changed in a stepless manner by changing the discharge amount.
Between the left and right hydraulic motors 17,17 and the left and right drive sprockets 11,11, left and right sub-transmission mechanisms 22,22 capable of shifting between high and low stages are respectively provided.

In the figure, 50 is a hydraulic pump, 42 is a swash plate control section for controlling the discharge amounts of the left and right hydraulic pumps 20, 20,
Reference numeral 43 is a hydraulic valve for shifting which is connected to the left and right sub-transmission mechanism 22,22, 51 is a hydraulic valve for braking which controls the hydraulic pressure to the hydraulic servo type brake 21, 54 is a brake pedal, 55 is a hydraulic oil tank, 56 Is an oil cooler and 57 is an oil filter.

FIG. 3 shows the construction of the operating unit 6, which is shown in FIG.
Is a vehicle speed control lever, 63 is an accelerator lever, 71 is an instrument panel, 72 is a one-touch lifting lever, 73 is a power takeoff lever, 74 is a parking lock lever, 75 and 76 are power takeout gearshift levers, 77 is a small article compartment, and 78 is mechanical auto. Is a positioning lever, 79 is a positioning lever, 80 is a lifting height control dial for the working unit, and 81 is an operation switch for rapidly lowering the working unit.

Further, the seat 5 can be freely rotated to the left and right to be fixed so that the driver can easily turn around backward to make the posture easier while getting in and out of the seat 5.

In such an agricultural tractor A, a three-point link mechanism 8 and an elevating mechanism 9 for connecting a working machine B such as a rotary type cultivator provided at the rear end of the machine frame 2 so as to be able to move up and down are as follows. Is configured as follows.

That is, as shown in FIGS. 1, 4 and 5, the left and right lower pivotal support portions 23, 24 are formed on the lower left and right sides of the rear surface of the traveling section frame 10 to form the left and right lower links 25, 3 of the three-point link mechanism 8. Twenty-six front ends are rotatably pivoted to
The front end of the top link 29 is rotatably pivotally attached to the upper center of the rear surface of the 10 through a cushioning mechanism 28, and the rear ends of the left and right lower links 25, 26 and the top link 29 are respectively rotatably attached to the work machine frame 30. The work machine B is connected to be movable up and down by being pivotally attached.

In particular, the left and right lower pivot portions 23 and 24 pivotally supporting the front end portions of the left and right lower links 25 and 26 and the cushioning mechanism 28 pivotally supporting the front end portion of the top link 29 are provided to the left and right of the crawler type traveling device 1. By arranging the crawler 16 in front of the rear end and inside the left and right crawlers 16, the total length when the working machine B is connected to the agricultural tractor A can be shortened and the turning radius can be shortened. .

That is, as shown in FIG. 1, the left and right lower pivot parts 23, 24 are located at substantially the same position as the front end parts of the left and right driven sprockets 12 which are pivotally supported by the left and right rear end parts of the traveling part frame 10, as shown in FIG. As shown in FIG. 5 when viewed from the rear, the cushioning mechanism 28 is arranged from the center of the cross member 33 that connects the rear ends of the left and right side members 31, 32 of the traveling frame 10.
By vertically arranging the 3P support 34 at the rear end of the traveling frame 10, and arranging the 3P support 34 at the center of the upper portion of the 3P support 34,
The left and right lower pivot parts 23 and 24, which respectively pivot the front ends of the left and right lower links 25 and 26 and the top link 29, and the buffer mechanism 28 are located in front of the rear ends of the left and right crawlers 16 and inside the left and right crawlers 16. It is arranged.

As shown in FIG. 6, the cushioning mechanism 28 has three
A pair of left and right support plates 90 are provided at the center of the upper portion of the P support body 34, and a swing plate 92 is rotatably pivotally mounted via a pivot 91 inserted through the lower portion of the support plate 90 to support the support plate. A spring 93 is interposed between the upper part of the 90 and the upper part of the oscillating plate 92, and the spring 93 elastically bears the forward load from the top link 29 pivotally attached to the middle part of the oscillating plate 92. Work machine B
The upper impact is received from the ground to prevent the top link 29 from being bent and the three-point link mechanism 8 from being damaged.

The oscillating plate 92 is interlocked with the position valve 65 of the hydraulic circuit, and when the oscillating plate 92 is displaced forward, the position valve 65 is switched so as to raise the working machine B, By raising the work implement B, a large impact can be dealt with.

As shown in FIG. 1, FIG. 4 and FIG. 5, the lifting mechanism 9 has left and right cylinder pivots 35 and 36 formed on the right and left sides slightly above and above the left and right lower pivots 23 and 24, respectively. The bottoms 39, 40 of the left and right lifting hydraulic cylinders 37, 38 are rotatably pivotally attached to the supports 35, 36, respectively, and the left and right lift arm pivotal supports 52, 53 are provided on the upper left and right sides of the 3P support 34, respectively. Form the left and right lift arm pivots 52,53
In addition, the front ends of the left and right lift arms 58 and 59, which are bent in a substantially V shape, are pivotally attached to the left and right lift arms 58 and 59, respectively.
The tip ends of the piston rods 60, 61 of the left and right lifting hydraulic cylinders 37, 38 are rotatably pivotally attached to the middle portions of 8, 59, and the rear end of the left lift arm 58 is oscillated via a swing hydraulic cylinder 62. The middle part of the left lower link 25 is interlockingly connected, and the rear end of the right lift arm 59 is connected to the right lower link via an ascending / descending connecting rod.
Hydraulic cylinders for left and right lifting 3
By the expansion and contraction operation of 7,38, the working machine B connected through the three-point link mechanism 8 is moved up and down to swing the hydraulic cylinder 62.
The work machine B is swung left and right by the expansion and contraction operation.

As described above, since the work machine B is moved up and down by the hydraulic cylinders 37, 38 for moving up and down the work machine B, it is possible to use a work machine having a wider width or a heavier work than a single hydraulic cylinder. The lifting and lowering operation of the machine becomes easy and the left and right balance is improved.

The left and right lifting hydraulic cylinders 37, 38 are
As shown in Fig. 2, the position valve is on the bottom 39, 40 side.
65, a safety valve 66, and a check valve 67 are connected in communication with a hydraulic case 68 connected to the hydraulic pump 50, and the rod sides 69 and 70 are connected to an operation switch 81 arranged in the operation unit 6 to switch the oil passage. Hydraulic case 68 via valve 82
When the operation switch 81 is pressed, the hydraulic pressure from the hydraulic pump 50 is also applied to the rod side 69, 70 by connecting it to the left and right lifting hydraulic cylinders 37, 38 to be retracted by the hydraulic pressure. Hydraulic cylinder 37,38
The operating direction of the can be changed.

The swing hydraulic cylinder 62 is connected to the hydraulic case 68 via a float control valve 83.

With this configuration, the position valve 65
Operate the bottoms 39,4 of the hydraulic cylinders 37,38 for left and right lifting.
Apply hydraulic pressure to the 0 side to move the left and right lifting hydraulic cylinders 37, 38
The work machine B is raised by extending the work machine B, the position valve 65 is switched, the hydraulic pressure on the bottom 39, 40 side of the left and right lifting hydraulic cylinders 37, 38 is drained, and the work machine B's own weight is used to lift the left and right lifting hydraulic cylinders 37, 38. The work implement B can be lowered by retracting 38.

Particularly, when the working machine B is rapidly lowered, the operation switch 81 is pressed to apply the hydraulic pressure from the hydraulic pump 50 to the rod sides 69 and 70 of the left and right lifting hydraulic cylinders 37 and 38. The left and right lifting hydraulic cylinders 37,38
Can be rapidly degenerated, and the work implement B can be rapidly lowered.

Further, as shown in FIG. 1, the power take-off shaft 84
In a side view, slightly forward of the rear ends of the left and right crawlers 16 and near the axis of the left and right driven sprockets 12, and the power take-off shaft 84 and the working machine B can be freely expanded and contracted to the universal joints 86 and 86 and the middle portion. The drive shaft 85 provided with the joint is interlockingly connected to transmit power from the agricultural tractor A to the working unit B.

In this way, by extending the power take-off shaft 84 to the vicinity of the axis of the left and right driven sprockets 12, the drive shaft 85 can be shortened and the drive shaft 85 can be shortened.
The weight of the drive shaft 85 can be reduced, and the work of attaching and detaching the drive shaft 85 can be facilitated, and the adverse effect of vibrations due to the rotation of the drive shaft 85 can be reduced.

Since the rear end of the power take-off shaft 84 does not project rearward from the rear ends of the left and right crawlers 16, the entire length of the agricultural tractor A alone does not extend. There is no obstacle to running or turning by itself.

[0035]

According to the present invention, in the agricultural tractor, which is equipped with a crawler type traveling device and in which a working machine is movably connected to the rear via a three-point link mechanism and an elevating mechanism, the above-mentioned three-point link mechanism is provided. The left and right lower pivots that pivotally support the front ends of the left and right lower links are arranged in front of the rear ends of the left and right crawlers of the crawler type traveling device and inside the left and right crawlers. It is possible to shorten the total length when connecting and to shorten the turning radius.

Further, since the lifting mechanism includes the left and right lifting hydraulic cylinders which are interlocked and connected to the middle portions of the left and right lift arms, respectively, the working machine having a wider width than that which is operated by one hydraulic cylinder is used. The lifting and lowering operation of a heavy work machine becomes easy, and the left and right balance is improved.

Further, the rod side of the left and right lifting hydraulic cylinders of the lifting mechanism is communicatively connected to the hydraulic pump through an oil passage switching valve connected to an operation switch provided in the operating section, and the left and right lifting hydraulic cylinders are connected. By making it possible to change the operating direction, not only to lower the work implement by its own weight, but also when lowering the work implement rapidly, press the operation switch to move the hydraulic pump to the rod side of the left and right lifting hydraulic cylinder from the hydraulic pump. The working machine can be rapidly lowered by causing the hydraulic pressure of (3) to act to rapidly retract the left and right lifting hydraulic cylinders.

Further, by extending the power take-off shaft for transmitting power to the working machine to the vicinity of the axial center of the left and right driven sprockets arranged at the rear end of the crawler type traveling device in a side view, By shortening the drive shaft between the tractor and the working machine, the drive shaft can be made lighter in weight, the mounting work can be facilitated, and the adverse effect of vibration associated with the rotation of the drive shaft can be reduced.

[Brief description of drawings]

FIG. 1 is a side view of an agricultural tractor including a work implement connection structure according to the present invention.

FIG. 2 is a hydraulic circuit diagram.

FIG. 3 is a schematic plan view showing the configuration of a driving unit.

FIG. 4 is a side view showing the configurations of a three-point link mechanism and a lifting mechanism.

FIG. 5 is a rear view showing the configurations of a three-point link mechanism and a lifting mechanism.

FIG. 6 is a side view showing the configuration of a buffer mechanism.

[Explanation of symbols]

 A Agricultural tractor B Working machine 1 Crawler type traveling device 6 Driving section 8 3-point link mechanism 9 Lifting mechanism 12 Driven sprocket 16 Left and right crawlers 23 Left lower pivot section 24 Right lower pivot section 25 Left lower link 26 Right lower link 37 Left lifting hydraulic Cylinder 38 Hydraulic cylinder for right and left 50 Hydraulic pump 58 Left lift arm 59 Right lift arm 69 Rod side 70 Rod side 81 Operation switch 82 Oil passage switching valve 84 Power take-out shaft

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masayuki Komiya 428 Enami, Okayama City, Okayama Prefecture Seirei Industry Co., Ltd.

Claims (4)

[Claims] 1. A working machine comprising a crawler type traveling device (1), and a rear three-point link mechanism (8) and a lifting mechanism (9).
In the agricultural tractor (A) in which (B) is vertically movable, the left and right lower pivot parts (23) (24) that pivotally support the front end parts of the left and right lower links (25) (26) of the three-point link mechanism (8). ) In front of the rear ends of the left and right crawlers (16) of the crawler type traveling device (1),
Further, the working machine coupling structure for an agricultural tractor is arranged inside the left and right crawlers (16). 2. A working machine equipped with a crawler type traveling device (1), and provided with a three-point link mechanism (8) and a lifting mechanism (9) on the rear side.
In the agricultural tractor (A) in which (B) is vertically movable, the left and right lifting hydraulic cylinders (37) (37) (where the lifting mechanism (9) is linked to the middle parts of the left and right lift arms (58) and (59) respectively. 3
8) An agricultural tractor working machine connection structure comprising: 3. A working machine comprising a crawler type traveling device (1), and a three-point link mechanism (8) and an elevating mechanism (9) in the rear thereof.
In the agricultural tractor (A) in which (B) is vertically movable, the rod side (69) (70) of the hydraulic cylinders (37) (38) for left and right lifting of the lifting mechanism (9) are connected to the operating section (6). ) Operation switch
Hydraulic pump via oil passage switching valve (82) connected to (81)
Hydraulic cylinder for left and right lifting (37) (38)
A working machine connection structure for agricultural tractors, characterized in that the operating direction of the can be changed. 4. A working machine comprising a crawler type traveling device (1), and a three-point link mechanism (8) and an elevating mechanism (9) in the rear thereof.
In the agricultural tractor (A) in which (B) is vertically movable, the power take-off shaft (84) for transmitting power to the working machine is arranged at the rear end of the crawler type traveling device (1) in side view. A structure for connecting a working machine of an agricultural tractor, characterized in that the left and right driven sprockets (12) are extended to the vicinity of the shaft center.